Aluminum vs Copper

As the demand for high-performance electric motors grows, material choice becomes critical for achieving optimal efficiency and power density. Traditionally, copper has been the standard for motor windings due to its high electrical conductivity. However, recent advancements in additive manufacturing (AM) and the development of semi-stranded winding designs have revealed that 3D printed aluminum offers distinct advantages over copper windings, especially for high-speed electrical machines.

Here’s why 3D printed aluminum is a better alternative to copper:

1. Weight Reduction: Aluminum’s low density, about one-third that of copper, leads to substantial weight savings. This is particularly beneficial in applications where weight is a critical factor, such as electric vehicles (EVs) and aerospace propulsion systems. The lightweight aluminum coils contribute to better energy efficiency and improved vehicle range.

2. Optimized Balance Between DC and AC Losses: The novel semi-stranded coil design, enabled by 3D printing, strikes an ideal balance between DC and AC losses. Unlike conventional copper windings, where AC losses dominate at higher frequencies, the semi-stranded aluminum design reduces eddy current losses, enhancing performance in high-frequency applications.

3. Lower Losses at Higher Frequencies: Copper’s high conductivity leads to higher AC losses due to the skin and proximity effects at high frequencies. Aluminum, with its higher resistivity, limits these effects, reducing eddy current losses. This makes aluminum windings particularly advantageous for high-speed electrical machines operating at high frequencies​.

4. Improved Temperature Uniformity: Under the same WLTP (Worldwide Harmonized Light Vehicles Test Cycle), aluminum windings demonstrate better temperature uniformity compared to copper. This results in lower thermal stress and improved reliability, which is critical for applications requiring long-term operational stability.

In conclusion, with its superior high-frequency performance, enhanced thermal properties, and significant weight savings, 3D printed aluminum is becoming a more attractive alternative to copper for modern electric motor windings.